请帮帮忙，小弟我贴代码了，现在不用下载文件看了

a.php  包含一个删除选中书签的复选框

function display_user_urls($url_array)
{
  // display the table of URLs

  // set global variable, so we can test later if this is on the page
  global $bm_table;
  $bm_table = true;
?>
  

  
}

点击上面删除的复选框后，需要点击下方的删除书签
  // only offer the delete option if bookmark table is on this page
  global $bm_table;
  if($bm_table==true)
    echo "Delete BM | "; 
  else
    echo "Delete BM | "; 
?>

delete_bms.php 删除函数如下
  require_once('bookmark_fns.php');
  session_start();
 
  //create short variable names
  $del_me = $HTTP_GET_VARS['del_me'];
  $valid_user = $HTTP_GET_VARS['valid_user'];
 
  do_html_header('Deleting bookmarks');
  check_valid_user();
  if (!filled_out($HTTP_GET_VARS))
  {
    echo 'You have not chosen any bookmarks to delete.
         Please try again.';
    display_user_menu();
    do_html_footer();  
    exit;
  }
  else 
  {
    if (count($del_me) >0)
    {
      foreach($del_me as $url)
      {
        if (delete_bm($valid_user, $url))
          echo 'Deleted '.htmlspecialchars($url).'.
';
        else
          echo 'Could not delete '.htmlspecialchars($url).'.
';
      }  
    }
    else
      echo 'No bookmarks selected for deletion';
  }
  // get the bookmarks this user has saved
  if ($url_array = get_user_urls($valid_user))
    display_user_urls($url_array);

  display_user_menu(); 
  do_html_footer();
?>

delete_bm函数的代码如下

function delete_bm($user, $url)
{
  // delete one URL from the database
  $conn = db_connect(); //此处已经包含在另一个php文件中，连接数据库是正常的
  // delete the bookmark
  if (!$conn->query( "delete from bookmark 
                       where username='$user' and bm_url='$url'"))
    throw new Exception('Bookmark could not be deleted');